This invention relates to surgical reattachment of soft tissue/ligament to bone, and more particularly, instrumentation for surgically securing an allograft or prosthetic ligament into a patient""s bone as part of a procedure to replace cruciate ligaments.
Surgical re-attachment of soft tissue to bone due to traumatic injury or surgical procedures has created a need for efficient and time-saving instruments, implants, and procedures. Current methods of re-attachment of soft tissue to bone include bone tunnels, surgical staples, surgical tacks, interference screws, and bone anchors. If the desired result is solely approximation of the soft tissue back to the bony insertion site, the aforementioned devices can be used within certain limitations. There are, however, certain tendons and ligaments, which present the surgeon with a very specific set of constraints, for example, grafting of a tendon into the site of an irreparably torn anterior cruciate ligament in the human knee.
Each repair technique has a unique set of constraints. For instance, interference screws are difficult to insert and can damage a graft on insertion. In order to insert an interference screw, a large hole must be drilled to accommodate the graft and the screw. The screw prevents bone to tendon fixation around the screw, can leave a weak defect in the bone, and can vascularize the area under compression. In another instance, bone tunnels require additional incisions and trauma to the patient. With a bone tunnel, there is little radial compression on the graft to the bone site and the securing suture may creep or be cut by the bone, and the securing knot may slip. With surgical staples, again additional incisions and trauma to the patient occurs, and there is little radial compression on the graft to the bone site. The surgical staple may even not stay in the bone. In another example, using a device having an internal screw in a tunnel and a ratcheting inner element that presses into the outer screw in anterior cruciate ligament (ACL) repair does not provide radial compression for graft healing. Also, such a device is difficult to revise.
A system of instrumentation and implants for surgically securing an allograft or prosthetic ligament into a patient""s bone is used in a procedure to replace a patient""s cruciate ligaments. In one general aspect, a fixation device for attaching soft tissue to bone includes a fixation mechanism, a shaft, and a securing mechanism, which slides along the shaft. The securing mechanism may include an internal one-way locking mechanism.
In another aspect, a device for attaching soft tissue to bone includes a shaft, a fixation mechanism attached to the shaft, a one-way track for inserting the shaft therein and the fixation mechanism therethrough; and a securing mechanism for holding a graft within the one-way track by compressing the securing mechanism against the graft. The securing mechanism may be at least one of a conical shape, a cylindrical shape, a cubic shape, or a complex shape capable of exerting an adequate radial force against the graft and into a surrounding bone. The fixation device may include a fixation mechanism with an expansion leg, a shaft with a one-way track, and a securing mechanism. The expansion leg of the fixation mechanism may be single or multiple legs or may be toggles, legs, expansion arms, barbs, tines, or other apparatuses to prevent backward translation. The one-way track of the shaft may be a single length or multiple lengths, i.e., an adjustable length member. The securing mechanism holds the tissue and has an internal one-way lock, which slides along the one-way track. Alternatively, the fixation mechanism may include an inner core that expands as a result of the insertion of a device that causes radial displacement, for example, a wedge, a tapered plug, or a screw.
A fixation device may be made of any biocompatible metal, such as titanium or stainless steel, plastic, such as nylon or polyester, or bioabsorbable, such as PLLA. Any material suitable for use in the body can be used. The material must provide adequate resistance to creep, hold the load required, and not be affected by cyclic loading.
The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features and advantages will be apparent from the description and drawings, and from the claims.